Use variable names directly in the format strings (#7906)

# Description

Lint: `clippy::uninlined_format_args`

More readable in most situations.
(May be slightly confusing for modifier format strings
https://doc.rust-lang.org/std/fmt/index.html#formatting-parameters)

Alternative to #7865

# User-Facing Changes

None intended

# Tests + Formatting

(Ran `cargo +stable clippy --fix --workspace -- -A clippy::all -D
clippy::uninlined_format_args` to achieve this. Depends on Rust `1.67`)

crates/nu-explore/src/commands/mod.rs

@@ -176,6 +176,6 @@ pub fn default_color_list() -> Vec<HelpExample> {
 
 pub fn default_int_list() -> Vec<HelpExample> {
     (0..20)
-        .map(|i| HelpExample::new(i.to_string(), format!("A value equal to {}", i)))
+        .map(|i| HelpExample::new(i.to_string(), format!("A value equal to {i}")))
         .collect()
 }